Wire or strip feeding mechanism for punch presses



Dec. 31, J, MacBLANE WIRE 0R STRIP FEEDING MECHANISM FOR PUNCH PRESSES 2 Sheets-Shet 1 Filed- Oct. 26, 1942 Dec. 31, 1946. I J. MacBLANE 2,413,638

- WIRE 0R STRIP FEEDING MECHNISM FOR PUNCH PRESSES Filed Oct. 26, 1942 2 Sheets-Sheet 2 INVENIOR.

J filacBla/w/ wanes/s; BY

. M 2 ATTORNEY I Patented Dec. 31,1946

UNITED STATE NT'Y OFFICE FOB PUNCH PRESSES James MacBlane, Elmira Heights, N. Y., aaslgnor to Bendix Aviation Co poration, South Bend, Ind a corporation of Delaware Application October 28, 1942, Serial No. 463,427

4 Claims. (Cl. 2-71-25) The present invention relates to wire or strip feeding mechanism for punch presses and more an arrangement which will maintain uniform feed pressure without undue complication and expense, that hand feed is still very largely used.

It is an object of the present invention to provide a novel feeding arrangement forraw material in the form of wire or strip stock which maintains a substantiallyconstant feed pressure irrespective of the travel of the stock in the feeder.

It is another object to provide such a device which may be adapted for feeding cut lengths of strip or rod stock, or for feeding wire or ribbon stock from a spool or roll.

It is another object to provide such a device which causes but a small amount of stock to be wasted.

It is another object to provide such a device which is simple and economical in construction and emcient and reliable in operation.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawings, in which:

Fig. 1 is'a, side elevation partly in vertical section of a preferred embodiment of the invention as' used to feed the bar stock into a forming 'die actuated by a punch press.

Fig. 2 is a detail of the end of'the feed cylinder showing the method of introducing the raw material and actuating piston;

Fig. 3 is .a section taken substantially on the line 3-3 of Fig. 1;

Fig. 4 is a view similar to Fig. 3 showing the valve-closure member in the loading position as illustrated in Fig. 2; and

Figs. 5 and 6 show in side elevation partly in section an embodiment of the invention adapted for the continuous feed of wire or ribbon stock from a spool or roll, Fig. 5 showing the receiving end of the device and Fig. 6 showing the delivery .end thereof.

that further description thereof-is believed to be unnecessary.

The raw material 3 used in the formation of the product is in the form of a rod or bar cut to as great a length as may be conveniently handled, and the present invention is concerned with the provision of means for feeding this raw material through the bushing i of the die -I as the rod is used up in forming the product. As here shown this is accomplished by means of a guide cylinder 6 which is made slightly longer than the rod of raw material and is supported at one end adiacentthe die I by a suitable bracket 8, and at its other end by a bracket 1. The bracket 1 has at its upper end a receiver block 8 which is drilled at 9 for the reception of the end of cylinder 8, and is also drilled at H to' receive the end of a conduit l2 conveying any suitable form of fluid pressure such as compressed air. The face it of block I is formed as a plane surface, and a valve-closure member H in the form of a cap is threaded on the block 8 as indicated at It and is provided with an interior plane surface It having a bearing fit on the surface i3 of the block.

The cap member I4 is provided with an interior groove II which is so positioned that when the cap is screwed up tightly against the block, the

groove is in registry with the openings 9 and il in the'block so as to form a passage for the fluid pressure from the conduit l2 to the cylinder 5. Cap I4 is provided with an opening it therethrough which is arranged to come into registry with the opening 9 of the block when the cap is unscrewed sufllciently to move the groove I! out of registry with openings 9 and II.

Means for actuating the rod 3 of raw material is providedin the form of a piston is slidably mounted in the cylinder 5 and provided with a socket 2| for receiving the end of the rod and imparting pressure thereto when the fluid pressure is admitted to the cylinder.

A sleeve 22 is slidably mounted in the opening ll of the block and is pressed against the interior of the cap it by suitable means such as a spring 23 so as to prevent escape of compressed air from the conduit l2 when the cap member is turned to its charging position as shown in Fig. 4. In the operation of this embodiment of the inventicn,the valve cap member I4 is rotated to the position shown in Fig. 4 so as to close the air pressure conduit and give accessto the end of cylinder 5. A rod of stock 3 is then inserted in the cylinder and started through the bushing 4 of the die. The piston I9 is then placed in the end of the cylinder 5 and the valve cap 14 rotated to operative position as shown in Fig. 3. The air pressure is then transmitted through the groove I! to the cylinder 5, causing the piston I! to maintain a constant feed pressureon the stock 3 to cause it to be advanced into the die as fast as it is used up. When the stock is substantially exhausted, the piston it emerges from theend of the cylinder and the operation of charging the feeding mechanism is repeated.

In the embodiment of the invention illustrated in Figs. 5 and 6, a continuous wire or strip 25 is arranged to be fed from a spool 26 into the bushing 38 of a cut-off and forming die 21 of the type above set forth; This is accomplished by means of a guide cylinder 28 mounted at one end in a bracket 29 adjacent the die 21 and at its other end in a fixed bracket 3| adjacent the spool of raw material. The receiving end of the cylinder 28 isprovided with a closure plug member 32 which is drilled at 33 to permit passage of the stock 25 and'is provided with a gripping device 34 which permits the stock to be fed therethrough, but prevents retrograde movement thereof.

The closure member 32 is provided with an axial passage 35 leading into the cylinder 28 and a radial passage 38 communicating therewith and registering with a passage 31 in a block 38 fixed in the bracket 3i. The block 38 is also provided with an opening 39 for the reception of a conduit 4| for fluid pressure, and with a rotary valve member 42. Valve 42 is so formed as illustrated that in one position it connects the passage 31 with the opening 39 so as to admit fluid pressure to the cylinder 28, and in the other position as illustrated in dotted lines in Fig. 5, it closes oif the fluid pressure and vents the cylinder to an outlet 43.

A piston member 44 which is axially drilled as shown at 48 to permit passage of the stock therethrough, is slidably mounted in the cylinder 28 and is normally maintainedin the retracted position illustrated by means of a light return spring 45. The piston member 44 projects from the discharge end of cylinder 28 as shown at 46 r and is there provided with a gripping device 41 which is arranged to transmit feeding pressure from the piston to the stock, but permits the piston to return to its normal position without transmitting backward movement to the stock.

the cylinder, whereupon the piston is returned to its normal'position by the spring 45. when the arm 48 is thus caused to engage the abutment 54 on link 52, the valve 42 is thereby moved,

to its open position and-the feeding operation is repeated.

7 Although but two embodiments of the invention have been shown and described in detail, it will be understood that other embodiments are possible and that various changes may be made in the design and arrangement of the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is: v

1. In an automatic stock feeding device for punch presses and the like, a guide cylinder for the stock, a piston slidably mounted in the cylinder and connected to advance the stock into the press, a source of fluid pressure adjacent the end of the cylinder remote from the press, and means for actuating the piston by said fluid pressure'comprising an opening for admitting the stock to said end of the cylinder and means preventing escape of air while the stock is being advanced.

2. In a continuous raw material feeding device for punch presses and the like, acylindrical guide for the raw material, a piston slidably mounted therein, gripping means for transmitting longitudinal movement of the piston to the raw material in .a direction to advance it into the press, gripping means for preventing retrograde movement of the raw material, means for admitting fluid under pressure to the cylinder to advance According to the present invention, means controlled by the movement of the piston are provided for actuating the valve 42 to cause reciprocation of the piston. As here shown this is accomplished by means of an arm 48 attached to the projecting end 48 of the piston and provided with an opening 48 through its lower end. Valve 42 is provided with an actuating crank 5|, and a link member 52 is pivoted to one end of the crank as shown at 58. The opposite end of the link 52 is arranged to traverse the opening 49 in the arm 48, and adjustable abutments 54 and 55 are mounted on the link in position to be engaged by said arm shortly before the piston reaches the end of its travel in either direction. In order to assure full travel of the valve 42, a toggle spring 55 is preferably provided, pivoted at one end at 51 to the bracket 3! and at its other end to the pivot 53 in the valve crank 5!.

In the operation of this embodiment, the stock is started through the opening 33 in plug 32 and through the piston 44 into the bushing 30 of the die 21. Fluid pressure is then supplied to the conduit 4| which acts on the piston 44 (valve 42 being open) and causes the stock to be fed into the die. As the stock is cut off and used by the 5| to swing the valve 42 to its dotted line position,

thus cutting off the fluid pressure and venting ment of the raw material, means for admitting the piston, means for withdrawing the piston, and valve means actuated by the movement of the piston for controlling the fluid pressure to cause reciprocation of the piston.

3. In a continuous raw material feeding device for unch presses and the like, a cylindrical guide for the raw material, a piston slidably mounted therein, gripping means for transmitting longitudinal movement of the piston to the raw material in a direction to advance it into the press, gripping means for preventing retrograde movefiuid under pressure to the cylinder to advance the piston, spring means for Withdrawing the piston, and valve means actuated by the movement of the piston for admitting fluid pressure to the cylinder until the piston reaches the end of its stroke, and then cutting ofi the pressure and venting the cylinder to allow return movement of the piston by the spring.

4. In a feeding mechanism for strip stock, a

cylinder of such length asto receive a strip of stock, open at one end adjacent a tool for operating on the stock, a piston in the cylinder adapted to engage and feed the stock through the open end of the cylinder, a rotatable closure for the other end of the cylinder, said closure having an opening therein as large as the bore of the cylinder and also having a diametrically arranged passage, a source of fluid pressure having a port coveredby said closure, said closure being so arranged that in one angular position the passage registers with the port and with the end of the cylinder so as to admit pressure to the cylinder and in another angular position the port is closed and said opening is in registry with'the bore of the cylinder to permit introduction of the stock and piston.

JAMES MAcBLANE. 

